Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets:
Investments	$ 60	$ 45
Foreign Exchange Contracts	20	2
Total Assets at Fair Value	80	47
Liabilities:
Foreign Exchange Contracts	14	29
Other	2	3
Total Liabilities at Fair Value	16	32
Fixed Rate Debt:
Carrying amount - Liability	4,072	3,128
Fair value - Liability	4,213	3,378
Variable Rate Debt:
Carrying amount - Liability	2,311	1,798
Fair Value - Liability	2,311	1,808
Quoted Prices in Active Markets for Identical Assets/Liabilities, Level 1
Assets:
Investments	60	45
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	60	45
Liabilities:
Foreign Exchange Contracts	0	0
Other	0	0
Total Liabilities at Fair Value	0	0
Significant Other Observable Inputs, Level 2
Assets:
Investments	0	0
Foreign Exchange Contracts	20	2
Total Assets at Fair Value	20	2
Liabilities:
Foreign Exchange Contracts	14	29
Other	2	3
Total Liabilities at Fair Value	16	32
Significant Unobservable Inputs, Level 3
Assets:
Investments	0	0
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	0	0
Liabilities:
Foreign Exchange Contracts	0	0
Other	0	0
Total Liabilities at Fair Value	$ 0	$ 0